Door-check.



D. E. WILLARD.

Patented May 18, 1915.

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D. ELWILLARD.

DOOR CHECK.

APPLICATION FILED JUNE 15, 1914.

[lily/J Patented May 18, 1915.

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DONALD E. VTILLARID, OF DANVILIAE, ILLINOIS.

DOOR-CHECK.

Specification of Letters Patent.

Patented May 18, 1915.

Application filed June 15, 1914. Serial No. 845,131.

To all whom it may concern Be it known that I, DONALD E. WILLARD, a citizen of the United States, and resident of Danville, in the county of Vermilion and tats of Illinois, have invented certain new and useful Improvements in Door-Checks, of which the following is a specification.

My invention relates to door checks and has particular reference to a novel checking device so constructed as to be cheaply manufactured, readily assembled or dismantled and which shall have means for varying the leverage or stroke of the piston with relation to the operating shaft.

One of the principal objects in the construction of my checking device is to provide means whereby the force of the spring is exerted to close the door against a varying resistance, the resistance being controlled by the escape of a fluid past the piston.

Another object is to provide means for directly connecting the reciprocating member and the shaft, which will permit a wide variation in the relative travel of the reciprocating member at different angular positions of the shaft, yet avoiding dead centers and allowing the shaft to rotate the required angle to actuate the door through a desired opening or angle, the movements in either direction of the reciprocating member being positive with respect to the shaft at all angular positions.

An object also in the present construction is to provide means for ready assembling of the parts. This is accomplished by providing a spring-seat which may be readily slipped into place from an open end of the casing and held in place by the rotation of a notched or threaded ring. The control of the passage of fluid from one side to the other of the piston is effected by means of a rod having an arcuate reduction therein. The finer control of the fluid is effected by means of the usual valve having suitable controlling means therefor.

The invention will be more readily understood by reference to the accompanying drawings, wherein,

Figure 1 is a longitudinal section through a check constructed in accordance with my invention; Fig. 2 is a similar longitudinal view taken at right angles to Fig. 1. Fig. 3 is a transverse section through the check at the point of the operating shaft; Fig. 4: is a section on the line 41-4 of Fig. 2; Fig. 5 is an end elevation with the closing cap removed, and, Fig. 6 is an elevation of the locking nut by means of which the spring seat is maintained in position.

Referring more particularly to the drawings it will be seen that I provide a casing 10, having attaching lugs or ears 11, and closed at one end by means of the wall 12. The opposite end is adapted to be closed by the cap 13, threaded on the end of the casing. l Vithin the casing I provide transverse, registering, threaded openings 14, within which gland plugs 15 are secured. These plugs provide a bearing for the dooroperating shaft 16, suitably packed to prevent the escape of liquid. Reciprocably mounted within the casing or cylinder is a piston 17, having a stem 18 secured therein. Within the piston are suitable ball check valves 19. The stem of the piston is provided with a plurality of notches 20, 21, 22, of varying depths as shown. Cotiperating with the notches in the stem are lever arms 23, 24, 25, having suitable anti-friction rolls 26, 27, 28, on the ends thereof. The levers 23, 24-, 25, are shown as formed in a single piece and are suitably secured against rotation on the shaft 16.

A compression spring 29 is mounted within the casing and bears at one end against the piston 17. The other end is held against movement by means of a block or cage 30, arranged to be inserted in the open end of the casing and to bear against the walls thereof. This block is provided with cutout portions 31, corresponding to the size of the inwardly projecting portions of the plugs. The block is thereby held against rotation. Pinned to the end of the block 30, is a ring 32, as best shown in Figs. 5 and 6, having ears 33, thereon which are adapted to register with notches 34:, formed in the open end of the casing 10. The notches 34:, are under-cut as shown and permit of the rotation of the ring in order to bring the cars 33 therein.

A regulating stem 35 is inserted with its forward end in the end wall 12, of the easing. This stem is provided as shown in Fig. 1, with an arcuate cut-out portion 36, the stem passing through an opening within the piston 17. As shown in Figs. 3, 4 and 5, the

stem 35 fits within a groove 37 formed in the side of the piston stem 18, and is held thereby. It will be understood that the stem 35 has no movement, the piston sliding thereon.

A by-pass 38 connects the cylinder at the front and rear'of the piston 18, a valve 39,

' site the shaft 16, from which the thrust is exerted. V

My improved check is assembled and operated as follows: The piston is first inserted within the casing followed by the spring 29. The cage or block 30 is next located, the spring being placed under suitable compression and the block and ring rotated to bring the ears 33, within the under-cut portions of the notches 34. The shaft 16, with the arms 23, 2 1, 25, thereon is next inserted, the arm 25 being located within the notch 22, in the piston stem. The plugs 15, are next located on the shaft and screwed into place. After the glands are tightened and the cap 13 locked, it being-assumed that the required amount of liquid is placed in the cylinder, the device is ready for operation.

7 It will be seen that during the first portion of the opening movement of the door the leverage between the shaft and the piston stem being considerable, the exertion of the spring and the checking resistance are multiplied. However, as the opening movement continues, the arm 24, is next brought into engagement, the radius of which is very small and as the exertion of the spring increases the same force will necessarily be exerted on the door-operating arm to cause its continued opening movement. As the door reaches the point near the end .of its opening movement the arm 23, comes into action, this arm having a slightly greater radius than the arm 24, and as the spring exertion is considerably increased the total exertion transmitted to the operating arm will be greatest at the point of extreme opening. It will be understood that there has been no fluid pressure to overcome due to the escape of the fluid through the check valves 19. However, as the door is released the check valves close and the liquid escapes through the cut-out portion 36, of the valve 35, as the piston is forced outward by the spring. A free action is given to the door during the intermediate portion of its closing movement. However, as the piston passes the cut-out portion 36, the entire es- I cape of liquid must be through theby-pass 38 which is controlled by the valve 39. At that point, as explained, the reduced exertion of the spring is multiplied by the longer leverage of the arm 25. Thus the door is positively closed at the point where the spring is usually the least active.

A considerable advantage in the present construction is in that the sorin must be placed in the casing with very little initial compression due to the multiplication of the bv the user from the outside by adjustment of the valve provided therefor.

The invention is capable of many modifications and such modifications as are within the scopeof my claims I consider within the spirit of my invention.

' I claim:

I 1. In a checking device, the combination of a cylinder and a piston therein, said pistonhaving a notched stem, a shaft. having a lever said lever being provided with'at least three arms projecting therefrom and adapted to cooperate with the notches in said stem the first of said arms to come into action being relatively long, the second arm being of a length no greater than the length of the third arm, substantially as described.

2. In a checking device, the combination of a cylinder, a spring-advanced piston having a notched stem,.a transverseshaft pro vided with a lever, said lever having at least three arms projecting therefrom, the first lever to come into action being relatively long, the second lever being shorter than the third lever, substantially as described.

3. In achecking device, the combination of a cylinder having an open end, a piston and a spring both of whichare adapted to be inserted through said open end, said, piston having a stem, anda spring-retaining barrel likewise insertible through the open end of said cylinder, a closing cap for the open end of said cylinder, and means independent of said closing cap for maintaining said barrel in position, substantially as described. Y

spring and a spring-retaining and piston-' V 4. In a checking device, the combination guiding block, all of Which parts are m sertible through the open end in said cylings of relatively large size,

inder, a closing cap, and a rotatable lock for maintaining said block and associated parts in position, substantially as described.

5. In a door check, the combination of a cylinder, a piston having a stem, a spring and a spring-retaining barrel, said barrel being provided with a guidevvay with Which the guiding member of said stem may cooperate, and means independent of the cylinder closing means for maintaining the parts in operative relation, substantially as described.

6. In a door check, the combination of a casing, a piston having a stem, a projection on said stem, a spring, and a spring-retaining and piston-guiding barrel insertible through an open end of said casing and provided With a groove Within Which the projection on said stem is guided, and means for closing the open end of said cylinder, substantially as described.

7 In a door check, the combination of a casing having an open end and provided With a pair of registering transverse opena piston having a stem, a spring, a spring-retaining block having a cut-out portion registering With said transverse openings, and a trans- Gopies of this patent may be obtained for verse shaft insertible through said registering portions and occupying the cut-out portion in said spring-retaining block, substantially as described.

8. In a door check, the combination of a casing having an open end, a piston having a grooved stein, a spring normally advancing said piston, a spring-retaining block insertible With said spring and piston through the open end of said casing, and a regulating rod secured to a portion of said casing and supported and guided in the groove in said stem, and a cap for closing the open end of said cylinder, substantially as described.

9. In a door check, the combination of a fluid cylinder having an open end, a piston, a spring-retaining block, and rotatable means independent of the means for closing the open end of said cylinder for locking said block Within said cylinder, substantially as described.

Signed at Chicago, Illinois, this 12th day of June, 1914.

DONALD E. WILLARD.

Witnesses:

C. F. MURRAY, T. D. BUTLER.

five cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

